Trying to identify caliber of single shot rifle

[mjtaa13]

Acquired a single shot rifle with barrel stamped Norm Joseph and a serial number. Appears to be a Falling Block Rifle Works from Rochester, Michigan from the stamping on the action. A 45-70 new case chambers in breech and ejects fine also. Is anyone familiar with this rifle maker, and is there an easy way other than a chamber casting to find out the caliber? Bore ID at muzzle is .451 using calipers.

Any help appreciated.

[tweedmus]

It's most likely a 45-70, 90, or 110 if it is a straight walled rimmed case (45-70 can be fired in any of these); also possibly 458 Winchester Magnum if the chamber indicates a belt. Usually there are caliber markings on the barrel.
The most certain way to find out is to make a chamber cast with a low temperature casting metal, available from Dixie Gun Works among others.

[Hgmeyer]

"Nobody cares until somebody loses an eye...", was always what I heard growing up. Well, anything short of a chamber cast just might get back to my youth...

[WIAKID]

Chamber cast. if you don't have cerrosafe, use sulphur.

[Jesselharrison]

"Nobody cares until somebody loses an eye...", was always what I heard growing up. Well, anything short of a chamber cast just might get back to my youth...

You are right. Having good caliber is very essential.